Kelloggs Cereal has been offering a program for several years now where you can earn an UNLIMITED number of AA Miles.
Here's how to do it.
1- Get an AA Advantage account number
2- Buy certain varieties of Kelloggs Cereal (The one's geared toward Adults, sorry NO kids type cereals are part of the program)
3- Save 5 certificates, fill them out and mail them to the address listed on the certificate that you cut out from the back of the box.
4- Your account will be credited 500 points.
There is a limit of 50 certificates per envelope mailed in, but you can mail as many as you like. I have been doing it now for about 2 years and have accumulated about 5000 miles. Not bad for eating a healthy breakfast every morning!